Obazu has been perfecting realistic gravity for quite a few years now, and it actually feels great to play with. Belive it or not he uses -70 for his mod and makes it work by buffing the strenght of the body.

You should test it out, it is a lot of fun and feels a lot more realistic. Punches hit harder and falling isn't floaty. It feels like fighting.

Here's a link to his uploads, the mods are marked higrav or hg